U.S. patent application number 10/860992 was filed with the patent office on 2005-07-28 for in mold manufacture of an object with embedded display panel.
This patent application is currently assigned to SiPix Imaging, Inc.. Invention is credited to Chaug, Y.S., Chung, Jerry, Dai, Feng Y., Liang, Rong-Chang, Tseng, Scott C.J., Wang, Xiaojia, Zang, HongMei.
Application Number | 20050163940 10/860992 |
Document ID | / |
Family ID | 33555432 |
Filed Date | 2005-07-28 |
United States Patent
Application |
20050163940 |
Kind Code |
A1 |
Liang, Rong-Chang ; et
al. |
July 28, 2005 |
In mold manufacture of an object with embedded display panel
Abstract
This invention relates to an object having a display panel
embedded in its top surface and processes for its manufacture.
Inventors: |
Liang, Rong-Chang;
(Cupertino, CA) ; Tseng, Scott C.J.; (San Jose,
CA) ; Chung, Jerry; (Mountain View, CA) ;
Zang, HongMei; (Sunnyvale, CA) ; Wang, Xiaojia;
(Fremont, CA) ; Chaug, Y.S.; (Cupertino, CA)
; Dai, Feng Y.; (Cerritos, CA) |
Correspondence
Address: |
HOWROY SIMON ARNOLD & WHITE, LLP
c/o IP DOCKETING DEPARTMENT
2941 FAIRVIEW PARK DRIVE, SUITE 200
FALLS CHURCH
VA
22042-2924
US
|
Assignee: |
SiPix Imaging, Inc.
|
Family ID: |
33555432 |
Appl. No.: |
10/860992 |
Filed: |
June 3, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60476852 |
Jun 6, 2003 |
|
|
|
Current U.S.
Class: |
428/1.1 ;
264/255 |
Current CPC
Class: |
B29C 33/60 20130101;
H04M 1/0283 20130101; B29C 43/021 20130101; B29L 2031/7232
20130101; G02F 1/133377 20130101; G02F 1/167 20130101; Y10T 428/10
20150115; B29C 43/18 20130101; C09K 2323/00 20200801 |
Class at
Publication: |
428/001.1 ;
264/255 |
International
Class: |
B28B 007/22 |
Claims
What is claimed is:
1-68. (canceled)
69. A plastic object having a display panel embedded in its top
surface.
70. The object of claim 69 which is formed by molding, stamping,
lamination or a combination thereof.
71. The object of claim 70 wherein said molding process is
injection molding, compression molding, thermoforming or blow
molding.
72. The object of claim 69 which is formed from a material selected
from the group consisting of thermoplastic materials, thermoplastic
elastomers, thermoset materials and blends, prepregs or composites
thereof.
73. The object of claim 69 wherein said display panel is an
electrophoretic display, liquid crystal display, flipping ball
display, liquid powder display, organic light-emitting diode,
display or polymer light-emitting diode display.
74. The object of claim 69 wherein said display panel is
Microcup.RTM. based.
75. The object of claim 73 wherein said liquid crystal display is a
polymer dispersed liquid crystal or a cholesteric liquid crystal
display.
76. The object of claim 69 wherein said display panel is formed on
a plastic substrate layer, sandwiched between two plastic substrate
layers or sandwiched between a transparent plastic layer and a thin
metal or metal oxide foil or a glass sheet.
77. The object of claim 76 wherein said metal or metal oxide foil
is formed from steel, Al, Sn, Ni, Cu, Zn, Mg or an alloy, oxide,
composite or blend thereof.
78. The object of claim 69 further comprising decorative designs on
said top surface.
79. The object of claim 78 wherein said decorative designs are
formed on the object by injection molding, compression molding,
thermoforming, blow molding, hot stamping, lamination or a
combination thereof.
80. The object of claim 69 which is the plastic cover of a cell
phone or pager.
81. The object of claim 69 which is a personal accessory, a toy or
educational device, a plastic cover of a personal digital assistant
or e-book, a credit or smart card or identification or business
card, the face of an album, watch, clock, radio or camera,
dashboard in an automobile, a household item, a laptop computer
housing, carrying case or front control panel of a consumer
electronic equipment.
82. An in-mold display transfer film or foil which comprises a
temporary carrier film, a release layer, a display panel, an
adhesive or tie layer and optionally a durable layer.
83. The in-mold display transfer film or foil of claim 82 wherein
said temporary carrier film is a thin film of PET, PEN or PC.
84. The in-mold display transfer film or foil of claim 82 wherein
said release layer is formed from wax, paraffin or silicone or a
highly smooth and impermeable coating prepared from a radiation
curable multifunctional acrylate, silicone acrylate, epoxide, vinyl
ester, vinyl ether, allyl or vinyl, unsaturated polyester or a
blend thereof.
85. The in-mold display transfer film or foil of claim 82 wherein
said release layer comprises a condensation polymer, copolymer,
blend or composite selected from the group consisting of epoxy,
polyurethane, polyimide, polyamide, melamine formaldehyde, urea
formaldehyde and phenol formaldehyde.
86. The in-mold display transfer film or foil of claim 82 wherein
said optional durable layer is formed from a radiation curable
multifunctional acrylate, epoxide, vinyl ester, diallyl phthalate,
vinyl ether or a blend thereof.
87. The in-mold display transfer film or foil of claim 82 wherein
said optional durable layer comprises a condensation polymer or
copolymer.
88. The in-mold display transfer film or foil of claim 82 wherein
said optional durable layer comprises a sol-gel silicate or
titanium ester.
89. The in-mold display transfer film or foil of claim 82 wherein
said adhesive layer is formed from polyacrylate, polymethacrylate,
polystyrene, polycarbonate, polyurethane, polyester, polyamide,
epoxy resin, ethylene vinylacetate copolymer, or thermoplastic
elastomer or a copolymer, blend or composite thereof.
90. The in-mold display transfer film or foil of claim 82 wherein
said adhesive layer is a hot melt or heat activated adhesive.
91. An in-mold display insertion film or foil which comprises a
carrier layer, a display panel and an adhesive layer.
92. The in-mold display insertion film or foil of claim 91 wherein
said display panel is formed directly on the carrier layer.
93. A process for the manufacture of an object having a display
panel embedded in the top surface of the object, which process
comprises: a) forming an in-mold display transfer film or foil
which comprises a temporary carrier layer, a release layer, a
display panel, an adhesive layer and optionally a durable layer; b)
feeding said in-mold display transfer film or foil into a mold with
said temporary carrier layer in contact with the inner surface of
the mold; c) forming said object by injecting a plastic material
into the mold, or thermoforming or blow molding with a plastic
material in the mold, or compression forming with a plastic
material in the mold; d) removing the object formed from the mold;
and e) simultaneously removing both said temporary carrier layer
and said release layer.
94. A process for the manufacture of an object having a display
panel embedded in the top surface of the object, which process
comprises: a) forming an in-mold display insertion film or foil
which comprises a carrier layer, a display panel and an adhesive
layer; b) inserting said in-mold display insertion film or foil
into a mold with said carrier layer in contact with the inner
surface of the mold; c) forming said object by injecting a plastic
material into the mold, or thermoforming or blow molding with a
plastic material in the mold, or compression forming with a plastic
material in the mold; d) removing the formed object from the mold.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 60/476,852, filed Jun. 6, 2003, the content of
which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an object having a display panel
embedded in its top surface and processes for its manufacture.
[0004] 2. Description of Related Art
[0005] Currently, for an object having a display panel, the object
and the display panel are manufactured separately and the two
components are then assembled together. The assembly of such an
object usually requires mechanical integration or lamination, which
typically results in a large gap between the object and the display
and also an increase in the total thickness or volume of the
object. Therefore, the current methods cannot meet certain product
requirements such as style, compactness and durability, which
features are especially important for handheld devices.
SUMMARY OF THE INVENTION
[0006] The first aspect of the invention is directed to an object
having a display panel embedded in its top surface. There may also
be decorative designs (e.g., text or graphic) appearing on the top
surface.
[0007] The second aspect of the invention is directed to an in-mold
display transfer film or foil.
[0008] The third aspect of the present invention is directed to an
in-mold display insertion film or foil. In this aspect of the
invention, a display panel may be formed on a carrier film
comprising an electrode layer.
[0009] The display panel in the in-mold display transfer film or
foil or in the in-mold display insertion film or foil may be any
plastic-based displays such as polymer dispersed liquid crystal
displays (PDLCs), cholesteric liquid crystal displays (ChLCD),
organic light emitting devices (OLEDs), electrophoretic displays
(EPDs) or other particle based displays.
[0010] The fourth aspect of the invention is directed to processes
for the manufacture of an object of the first aspect of the
invention.
[0011] The present invention has a wide variety of applications.
For example, the object may be a plastic cover of a cell phone or
pager and the display panel embedded in the top surface may display
text messages, time and dates and/or colored or flashing signals
alerting the user to incoming phone calls or number of voice mail
messages. In fact, the invention is useful for any objects which
are made of a plastic material, such as personal accessories (e.g.,
handbags or wallets), toys or educational devices, plastic cover of
a personal digital assistant or e-book, credit or smart cards,
identification or business cards, the face of an album, watch,
clock, radio or camera, the dashboard in an automobile, household
items (e.g., cups, dishes or bottles), laptop computer housings and
carrying cases or front control panels of any consumer electronic
equipments. This list is clearly not exhaustive. Other applications
would be clear to a person skilled in the art and therefore they
are all encompassed within the scope of the present invention.
[0012] When a plastic display is embedded in an object, the
seamless integration produces a very appealing look. The display
panel may conform to the object surface, even if the surface is
curved. As a result, the display panel may appear as one integral
or printed part of the object. According to the present invention,
large size plastic displays may also be embedded in an object,
which would be impossible to achieve with traditional display
assembly technology.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Various embodiments of the invention are disclosed in the
following detailed description and the accompanying drawings.
[0014] FIG. 1 shows the top view of an object of the present
invention.
[0015] FIG. 2a is a cross-section view of an in-mold transfer film
or foil comprising a display panel.
[0016] FIG. 2b is a cross-section view of an in-mold insertion film
or foil comprising a display panel.
[0017] FIG. 2c is an enlarged view of a typical plastic-based
display panel.
[0018] FIG. 3a is the cross-section view of an injection molding
process involving an in-mold transfer film or foil.
[0019] FIG. 3b is the cross-section view of an injection molding
process involving an in-mold insertion film or foil.
[0020] FIGS. 4a and 4b illustrate an object of the present
invention having an inner cavity.
[0021] FIGS. 5 and 6 illustrate application of decorative designs
to an object of the present invention.
DETAILED DESCRIPTION
[0022] The invention can be implemented in numerous ways, including
as a process, an apparatus, a system, a composition of matter, a
computer readable medium such as a computer readable storage medium
or a computer network wherein program instructions are sent over
optical or electronic communication links. In this specification,
these implementations, or any other form that the invention may
take, may be referred to as techniques. In general, the order of
the steps of disclosed processes may be altered within the scope of
the invention.
[0023] A detailed description of one or more embodiments of the
invention is provided below along with accompanying figures that
illustrate the principles of the invention. The invention is
described in connection with such embodiments, but the invention is
not limited to any embodiment. The scope of the invention is
limited only by the claims and the invention encompasses numerous
alternatives, modifications and equivalents. Numerous specific
details are set forth in the following description in order to
provide a thorough understanding of the invention. These details
are provided for the purpose of example and the invention may be
practiced according to the claims without some or all of these
specific details. For the purpose of clarity, technical material
that is known in the technical fields related to the invention has
not been described in detail so that the invention is not
unnecessarily obscured.
[0024] FIG. 1 shows the top view of an object (10) comprising a
display panel (11) embedded in its top surface. Text or graphic
design (12) may also optionally appear on the top surface. The term
"embedded", in the context of the present invention, is intended to
indicate that the display panel is integrated into the top surface
of the object when the object is being formed, not after the object
is formed.
[0025] The manufacturing process suitable for the formation of the
object may include, for example, hot stamping, lamination,
injection molding, thermoforming, compression molding or blow
molding. Examples of the material suitable for the object in the
stamping, lamination or molding process may include, but are not
limited to, thermoplastic materials such as polystyrene, polyvinyl
chloride, acrylics, polysulfone, polyarylester, polypropylene
oxide, polyolefins, acrylonitrile-butadiene-styrene copolymers
(ABS), methacrylate-acrylonitrile-butadiene-styrene copolymers
(MABS), polycarbonate, polybutylene terephthalate (PBT),
polyethylene terephthalate (PET), polyurethanes and other
thermoplastic elastomers or blends thereof, and thermoset materials
such as reaction injection molding grade polyurethanes, epoxy
resin, unsaturated polyesters, vinylesters or composites, prepregs
and blends thereof.
[0026] (I) In-Mold Display Transfer Films or Foils
[0027] In the manufacture of the object of the present invention,
an in-mold display transfer film or foil comprising a display panel
is first prepared.
[0028] Although the term "in-mold" is used throughout this
application, it is understood that the present invention can be
extended to processes such as stamping, lamination or a combination
of stamping or lamination and a molding process.
[0029] FIG. 2a is a cross-section view of such an in-mold display
transfer film or foil (20) which comprises a temporary carrier
layer (21), a release coating (22), an optional durable coating
(23), a display panel (24) and an adhesive or tie-coat layer (25).
The release layer (22), the durable layer (23) if present, the
display panel (24) and the adhesive layer (25) are sequentially
coated or laminated onto the carrier film (21) and these different
layers are collectively referred to as the "in-mold display
transfer film or foil" throughout this application for ease of
illustration.
[0030] In the in-mold transfer process, the in-mold display
transfer film or foil is fed into the mold with the temporary
carrier layer (21) in contact with the mold surface.
[0031] The key element, the display panel (24) may be a
particle-based display such as a flipping ball display as described
in T. Pham, et al, SID 02 Digest, p. 119 (2002); a liquid powder
display as described in R. Hattori, et al, SID 03 Digest, p. 846
(2003); or an electrophoretic display, particularly a Microcup.RTM.
EPD as disclosed in co-pending applications, U.S. Ser. No.
09/518,488 (corresponding to PCT/US01/06917), U.S. Ser. No.
09/879,408 (corresponding to WO02/100155), U.S. Ser. No. 10/447,719
(corresponding to WO03/102673), U.S. Ser. No. 10/422,413
(corresponding to WO03/91798), U.S. Ser. No. 10/422,557
(corresponding to WO03/91788) and U.S. Ser. No. 60/375,936, the
contents of all of which cited above are incorporated herein by
reference.
[0032] The electrophoretic display may have a traditional up/down
switching mode. It may have an in-plane or a dual switching mode as
disclosed in co-pending applications, U.S. Ser. No. 10/198,729
(corresponding to WO03/009059) and U.S. Ser. No. 10/222,036
(corresponding to WO03/016993) respectively, the contents of both
are incorporated herein by reference.
[0033] The display panel may also be an OLED (organic light
emitting device), a PLED (polymer light emitting device) or a
liquid crystal display, particularly a polymer dispersed liquid
crystal (PDLC), Microcup.RTM. LCD [as disclosed in co-pending
applications, U.S. Ser. No. 09/759,212 (corresponding to
WO02/56097) and U.S. Ser. No. 10/178,990, the contents of both are
incorporated herein by reference] or a cholesteric liquid crystal
device (ChLCD). Reviews of reflective displays including PDLC and
OLED/PLED can be found in the books, P. S. Drzaic, "Liquid Crystal
Dispersions", World Scientific Publishing Co. (1995); S-T. Wu and
D-K, Yang "Reflective Liquid Crystal Displays", John Wiley &
Sons, (2001); and R. Hattori, et al, SID 03 Digest, p. 846 (2003),
respectively, the contents of all of which are also incorporated
herein by reference.
[0034] The display panel is preferably thin and flexible and the
substrate used for the formation of the display panel preferably
has a high heat distortion temperature to allow the display to
withstand the process conditions in the transferring process, such
as injection molding or other molding conditions. A plastic based
display panel is preferred. The term "a plastic-based display
panel", in the context of the present invention, refers to a
display panel which is formed on a plastic substrate layer,
sandwiched between two plastic substrate layers or sandwiched
between a transparent plastic layer and an insulator-coated thin
metal or metal oxide foil or a glass sheet. The metal or metal
oxide foil may be formed from steel such as carbon steel or
stainless steel, Al, Sn, Ni, Cu, Zn, Mg or alloys, oxides,
composites or blends thereof.
[0035] FIG. 2c is an enlarged view of a plastic-based Microcup.RTM.
display panel. The panel (24) has a plurality of display cells
(26), a top electrode plate (27a) and a bottom electrode plate
(27b). The display panel may be formed on a bottom plastic
substrate layer (28b), laminated with a top plastic substrate layer
(28a) or both. Suitable materials for the plastic substrate
layer(s) may include polyethylene terephthalate (PET), polybutylene
terephthalate (PBT), polyethylene naphthalate (PEN), polyolefins
including polycyclic olefins, polycarbonate (PC), polymethyl
methacrylate (PMMA), polysulfone, polyimide (PI), polyarylester,
polystyrene, polyurethane, polysiloxane and copolymers, blends or
composites thereof, with PET, PBT, PEN and PC as preferred.
[0036] In a Microcup.RTM.-based display, the display cells (26) are
individually top-sealed with a sealing layer formed from a material
selected from the group consisting of thermoplastics, thermoplastic
elastomers, thermosets and precursors thereof.
[0037] For the display panel, either the side of the top electrode
layer (27a) or the side of the bottom electrode layer (27b) may be
the viewing side. In other words, in the in-mold display transfer
film or foil, either the side of the top electrode layer or the
side of the bottom electrode layer may be in contact with the
release layer (22) or the durable layer (23), if present, in the
molding process.
[0038] In the case of in-plane switching EPD which comprises an
in-plane electrode substrate and an insulator substrate, the
viewing side is preferably the insulator side to simplify the
connection to the display driver and outside circuitries.
[0039] The temporary carrier layer (21) usually is a thin plastic
film with a thickness from about 3.5 to about 50 microns. PET, PEN
and PC films are particularly preferred because of their low cost,
high transparency and thermomechanical stability.
[0040] The release coating (22) of the in-mold transfer display
film allows the display panel coating to release from the carrier
in a manner that minimizes damage to the display panel and enables
a fully automated roll transfer process during molding.
[0041] The release coating usually is a low surface tension coating
prepared from a material such as wax, paraffin or silicone or a
highly smooth and impermeable coating prepared from a material such
as radiation curable multifunctional acrylates, silicone acrylates,
epoxides, vinyl esters, vinyl ethers, allyls and vinyls,
unsaturated polyesters or blends thereof. The release layer may
comprise a condensation polymer, copolymer, blend or composite
selected from the group consisting of epoxy, polyurethane,
polyimide, polyamide, melamine formaldehyde, urea formaldehyde and
phenol formaldehyde.
[0042] The optional durable coating (23) serves as a protective
layer to the display panel (24) and the ink or metal patterns, if
present. Suitable raw materials for the durable coating may
include, but are not limited to, radiation curable multifunctional
acrylates including epoxy acrylates, polyurethane acrylates,
polyester acrylates, silicone acrylates, glycidyl acrylates,
epoxides, vinyl esters, diallyl phthalate, vinyl ethers and blends
thereof. The optional durable coating may comprise a condensation
polymer or copolymer, such as epoxy, polyurethane, polyamide,
polyimide, melamine formaldehyde, urea formaldehyde or phenol
formaldehyde. The optional durable coating may comprise a sol-gel
silicate or titanium ester.
[0043] The durable layer of the in-mold transfer display film may
be partially or fully cured. If partially cured, a post curing step
will be employed after the molding and/or transferring step to
enhance the durability, particularly hardness, scratch and oil
resistance.
[0044] To improve the release properties, the raw material,
particularly the low molecular weight components of the durable
layer is preferably not permeable into the release layer. After the
durable layer is coated and cured or partially cured, it should be
marginally compatible or incompatible with the release layer.
Binders and additives such as thickeners, surfactants, dispersants,
UV stabilizers or antioxidants may be used to control the rheology,
wettability, coating properties, weatherability and aging
properties. Fillers such as silica, Al.sub.2O.sub.3, TiO.sub.2,
CaCO.sub.3, microcrystalline wax or polyethylene, Teflon or other
lubricating particles may also be added to improve, for example,
scratch resistance and hardness of the durable layer. The durable
layer is usually about 2 to about 20 microns, preferably about 3 to
about 8 microns in thickness. The durable layer in the areas
covering the display panel is preferably transparent.
[0045] When the durable layer (23) is not present, the top
substrate layer (28a) or the bottom substrate layer (28b) in the
display panel (24) may serve as a protective layer. In this case,
the display substrate layer on the viewing side may extend beyond
the display panel area and covers part or all of the release film
of the transfer film or foil. The display panel (24) may be
laminated directly onto the release layer or the durable layer, if
present, optionally with an adhesive (not shown).
[0046] The adhesive layer (25) is incorporated into the display
panel coating to provide optimum adhesion of the display panel (24)
and the ink or metal patterns, if present, to the top surface of
the molded object. The adhesive layer may be formed from a material
such as polyacrylate, polymethacrylate, polystyrene, polycarbonate,
polyurethane, polyester, polyamide, epoxy resin, ethylene
vinylacetate copolymers (EVA), thermoplastic elastomers or the
like, or copolymers, blends or composites thereof. Hot melt or heat
activated adhesives such as polyurethane and polyamide are
particularly preferred. The thickness of the adhesive layer may be
in the range of about 1 to about 20 microns, preferably in the
range of about 2 to about 6 microns.
[0047] If a durable layer is present, printed ink or metal patterns
may be present between the display panel (24) and the durable layer
(23) or between the durable layer (23) and the adhesive layer (25)
in the areas that no display is present. If the durable layer is
not present, the printed ink or metal patterns may be present on
the display panel as illustrated in Section IV below.
[0048] (II) In-Mold Display Insertion Films or Foils
[0049] FIG. 2b is a schematic cross-section view of an in-mold
display insertion film or foil. In this case, the carrier layer
(21a) will become part of the finished product after the stamping,
lamination or a molding process. The display panel (24) may be
laminated onto the carrier film (21a) with an adhesive layer (not
shown) and optionally over-coated on the other side with a hot melt
or heat activated adhesive (25). Alternatively, the display panel
may be prepared directly on the carrier film by methods known in
the art, for example, the methods as described in co-pending
application, U.S. Ser. No. 09/518,488. In this case, the carrier
film may comprise a transparent electrode layer such as indium-tin
oxide (ITO).
[0050] Similar to the in-mold display transfer film or foil,
printed ink and metal patterns may be present between the display
panel and the carrier film or between the carrier film and the
adhesive layer (25) in the areas that no display is present. These
different layers are collectively referred to as the "in-mold
display insertion film or foil" throughout this application for
ease of illustration.
[0051] (III) Manufacture of the Object
[0052] A typical in-mold transfer process is illustrated in FIG.
3a. In the molding process, the in-mold display transfer film or
foil is on a roll or web continuously fed into a molding machine.
The mold (30) may be an injection or compression mold for the
object (36b). During the molding process, the mold is closed and
the plastic melt for the formation of the object is injected into
the mold cavity (36a) through injection nozzles and runners. After
molding, the display panel, the durable layer if present, and also
the ink and metal decoration patterns, if present, are transferred
onto the molded object. The molded object is removed from the mold.
The temporary carrier layer (31) and the release layer (32) are
also simultaneously removed leaving the durable coating (33), if
present, to be the top-most layer on the surface of the object with
the display panel (34) embedded underneath as an integral part of
the object. The layer (35) is an adhesive layer.
[0053] To facilitate the registration of the display transfer film
to the mold, the roll or web may be pre-printed with registration
marks and continuously fed into the mold with registration by, for
example, an optical sensor.
[0054] When the durable layer (33) is not present, one of the
plastic substrate layers of the display panel (34) would be the
top-most layer on the surface of the object.
[0055] In an in-mold insertion process as illustrated in FIG. 3b,
an in-mold display insertion film or foil is first cut into an
appropriate size and shape and then inserted into a mold (30). The
in-mold display insertion film is placed against the mold wall as
shown, optionally under vacuum. The display panel coating can be
placed manually, an electrostatic charge may be used to facilitate
its insertion or the insertion may be mechanized. Mechanized
insertion is advantageous especially for large volume
production.
[0056] The carrier layer (31a) of the display insertion film is in
contact with the inner wall surface of the mold. The mold is then
closed and the plastic melt for the formation of the object (36b)
is injected into the mold cavity (36a) through injection nozzles
and runners. The carrier film (31a) in this case may become an
integrated part of the finished product. Optionally, the display
insertion film may be thermoformed to a certain shape and die cut
before being inserted into the mold.
[0057] The mold used for either of the two types of manufacturing
process must be designed with the display panel insertion or
transfer in mind. Gate locations must allow the display panel to be
pressed up against the mold cavity to assure adequate thermal
transfer through the various layers in the display panel. Also, the
mold must be so designed that the electrodes of the display panel
after the molding process may be exposed for subsequent connection
to display driver and outside circuitries. In addition, mold flow
and filling analysis should be performed prior to cutting of the
mold material. A mold cooling analysis should also be considered to
minimize mold hot spots. Finally the mold temperature settings must
take into account the presence of the display panel.
[0058] The connectors which connect the display panel to outside
circuit and driver are not shown in either FIG. 2a or FIG. 2b. The
in-mold display transfer film or foil or the in-mold display
insertion film or foil may be in the form of a roll.
[0059] FIG. 4a is a cross-section view of a solid object with a
display panel embedded in its top surface. The object (40) may have
connection cavity in the form of open holes or slots (41) in the
body as shown to allow connection of the display panel (42) to the
required circuitries. The electrodes (43) of the display are routed
and exposed through the holes or slots for driver connection. A
flex cable (44), or other types of flexible connection harness, can
be attached to the electrodes by either conductive adhesive (45),
such as ACF, conductive PSA or silver paste, or mechanical
clamping.
[0060] FIG. 4b illustrates a snap-in plug (46) that can be further
inserted to secure the bonding area and enhance the reliability of
the electrode connection. For a direct drive display, the common
electrode is positioned on the viewing side, which is applied on
the carrier film in the case of in-mold display insertion film or
foil. The segment electrodes of the direct drive display are routed
through vias (through holes) to the connection pads, which are
positioned on the rear surface of the display. For an active matrix
display, the common electrode is positioned on the viewing side and
the flexible active switching component layer is positioned at the
non-viewing side. Signal connection pads are located on the rear
surface of the display and connected to the active switching
components through vias. For a passive matrix display, all row
electrodes and column electrodes should be routed to the rear
surface to ease the connection process. The routing can be achieved
through vias or flexible circuit adaptors. In the three types of
display, namely, direct drive, active matrix and passive matrix,
the display drivers (47) can be optionally installed on the display
to reduce the number of connection pads, which can further improve
connection quality and reduce manufacturing cost.
[0061] Alternatively, the object may be formed by blow molding or
thermoforming to create an inner cavity to accommodate the
circuitries. For manufacturing an object by blow molding or
thermoforming, the display transfer or insertion film is first
placed into an open mold and held in place by, for example, vacuum
or tension; the mold is then closed. The plastic material for
forming the object is thermoformed or blown into the mold. The
display panel, like in the injection or compression molding
process, is adhered to and embedded in the top surface of the
molded object such as a cup or bottle.
[0062] Alternatively the object may be formed by other molding
processes such as compression molding, hot stamping or
lamination.
[0063] (IV) Application of Decorative Designs
[0064] Text and/or graphic designs may also appear on the top
surface of the object. The most common designs include brand names,
logos or symbols or other decorative designs.
[0065] Traditional methods for adding decorative designs have
included screen printing, pad printing, hot stamping, lamination
and painting. These methods historically have been post-molding
operations that require additional processing steps.
[0066] In recent years, alternative decoration methods, such as
in-mold foil, insert molding or sublimation heat transfer has been
used. FIGS. 5 and 6 illustrate the in-mold decoration
processes.
[0067] FIG. 5 is an enlarged view of a display panel in an in-mold
display transfer or insertion film. The display panel comprises a
plurality of display cells (50), a top electrode layer (51), a
bottom electrode layer (52) and a top plastic substrate layer (53).
The decorative designs may be screen printed on the first surface
(54) or the second surface (55, the back side) of the top plastic
substrate layer. The bottom electrode layer (52) is disposed on a
bottom substrate layer (57) which may be bonded to the plastic
molded object (not shown) with an adhesive or a tie layer (not
shown). The bottom substrate layer may be a plastic layer as
described above or an insulator-coated metal or metal oxide foil
formed from carbon steel, stainless steel, Al, Sn, Ni, Cu, Zn, Mg
or an alloy or oxide thereof.
[0068] FIG. 6 shows an alternative in which the decorative designs
are printed on the first surface (64) of the top plastic substrate
layer (63) which is underneath the top durable layer (66) or on the
second surface (65) of the top substrate layer (63) which is above
the first electrode layer (61) of the display. If the decoration
pattern is on the first surface (64), a durable layer (66) above is
highly desirable to improve the hardness, scratch and oil
resistance of the surface. Similar to the in-mold display film
described in FIG. 5, the bottom electrode layer (62) is disposed on
a bottom substrate layer (67) which may be bonded to the plastic
molded object (not shown) with an adhesive or a tie layer (not
shown). The bottom substrate layer may be a plastic layer as
described above or an insulator-coated metal or metal oxide foil
formed from carbon steel, stainless steel, Al, Sn, Ni, Cu, Zn, Mg
or an alloy or oxide thereof.
[0069] The decorative designs may also be formed by thermoforming.
In this case, the carrier film will become part of the molded
object and the total decorative layer having raised or recessed
patterns is typically in the range of about 0.2 to about 1 mm,
preferably in the range of about 0.3 to about 0.7 mm in thickness.
It is usually thermoformed from an ABS, polystyrene or PVC sheet in
a mold.
[0070] Alternatively, the decorative layer may be also formed by
high pressure forming involving the use of high-pressure air to
create decorative designs on a film. The decorative layer may also
be formed by hydroforming in which a hydrostatic bladder, rather
than air, serves as the forming mechanism.
[0071] It should also be noted that the decorative layer prepared
from either one of the methods described above must have the
decorative designs strategically printed in areas which do not
overlap with the display panel. In other words, the decorative
designs should not interfere with the display image.
[0072] While the present invention has been described with
reference to the specific embodiments thereof, it is understood
that various changes may be made and equivalents may be substituted
without departing from the true spirit and scope of the invention.
In addition, many modifications may be made to adapt to a
particular situation. All such modifications are intended to be
within the scope of the present invention.
[0073] Although the foregoing embodiments have been described in
some detail for purposes of clarity of understanding, the invention
is not limited to the details provided. There are many alternative
ways of implementing the invention. The disclosed embodiments are
illustrative and not restrictive.
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